Retrievable subsurface well tool



Jan. 12, 1954 R. BAKER RETRIEVABLE 'SUBSURFACE WELL TOOL 2 Sheets-Sheet l Filed Jan. G, 1950 Jan. 12, 1954 R. c. BAKER RETRIEVABLE SUBSURFACE WELL TOOL 2 Sheets-Sheet 2 Filed Jan. 6, 1950 REL/BEN C. BAKE@ INVENTR.

@zaga/ @j )awww /QTTUQNEYJ Patented Jan. 12, 1954 UNITED STATES PATENT OFFICE a 2.665.764 RETamvAeLE sUsUaFAcE WELL '.rooL

llteuben C. Baker, Coalinga, Calif., assigner to Baker Oil Tools, Inc., Los Angeles, Calif., a cor-i poration of California Application January 6, 1950, Serial No. 137,164

(Cl. 16S-12) 18 Claims.

The present invention relates to subsurface well tools, and more particularly to tools useful in the performance` of cementing, acidieing, washing, testing, anchoring, production and other operations in well bores.

The operation of certain types of well tools is accomplished by moving their parts relatively to each other through the manipulation oi tu# bular strings to which the tools are attachable. As anexarnple, thetubular string may be inanipulated for shifting casing engaging slips along a cooperable expander and outwardly against a well casing. The relative movement may be obtainable by resisting or preventing movement of one or more of the tool parts through the use of instrumentalities engaging Vthe wall of the Well conduit or formation. These instrumenn talities may include friction springs and the like that are slidable along the conduit wall.` Al though resistance to movement is required during the performance of some of the operations in the well bore, such resistance is not" always desirable. To illustrate, removal of the well tool from a casing is expedited if the tubing or drill joints are unscrewed by holding the section above the rotary table stationary and rotating the remainder of the tubular string and the well tool in the hole. This rotation also revolves the casing engaging instrnmentaiities, such as friction `drag springs, slidingor dragging them around and along the casing wall, with potential damage to the instrumentalities and to other parts of the well tool.

An object of the invention is to provide a tool embodying a drag `device for controlling operation oi the tool, in which improved means are available for insuring the uncoupling of the drag device from the remainder of the tool, in order that the drag device need not be rotated during rotation off the tubular string secured to the tool.

Another object oi the invention is to provide a well tool including casing engaging' slips and a casing engaging drag device for controlling eX- pansion and retraction of the slips against and from a well casing, in which improved means are provided for releasing the drag device, to per- `mit rotation of the Atool Without rotating the drag device around the Wall of the casing.

The `aforementioned drag device may be threadedly connected to other portions of the tool when the drag device is in operative position. The drag device is unthreaded completely from such other portions to effect its uncoupling therefrom. The weight of certain parts of the tool may cause their engagement with the threaded portion of the drag device after the Latter has been uncoupled, causing potential damage to the threadsof the drag device during ro- Rf it?? 15991 me. Well WT@ Accordingly, a further object of the invention is to prevent or minimize such engagement with the drag device threads after the latter has` been uncoupled from'the remainder of the tool.

Yet another object oi the invention is to counterbalance the weight of slips and associated elements in a well tool to offset any tendency for the slips to shift inadvertently to expanded position.

This invention possesses many other advantages, and has other objects which may be made more clearly apparent from a consideration of a form in which it may be embodied. This form is shown in the drawings accompanying and forniing part of the present speciication. It will n ow be described in detail, 'for the purpose o'illusgtrating the general principles of the invention; but it is to be understood that such detailed description is not to be taken in a limiting sense, since the scope of the invention is best dened by the appended claims.

Referring to the drawings: p

Figure i is a longitudinal section, with` parts in elevation, of a retrievable well packer disposed within a casing, With 'the packer parts in retracted position;

Fig. 2 is an enlarged longitudinal section through the drag and lock portion of the tool, with the drag device rotatably uncoupled from the remainder of the tool;

Fig. 3 is a view similar to Fig. 1 of the well packer anchored in packed-01T condition within the well casing;

Fig. 4 is a cross-section taken 4-4 on Fig. 1;

Fig. 5 is a cross-secton taken along the line 5-5 on Fig. 1;

Fig. 6 is a cross-section taken along the line 6 6 on Fig. l; i

Fig. 7 is a cross-section taken along the line 'vi-1 on Fig. 3

The invention is exemplied in the drawings as applied to a well packer A of the retrievable type. It is to be understood, however, that the invention is also applicable to other welltools, and for controlling elements other than slips and packings hereinafter referred to.

The packer A is adapted to be run in a well bore or casing B on the end of a tubular run'- ning-in string C threadedly, or otherwise attached, to the upper end of the tubular mandrel or body portion Iii o=f the packer. The lower end of this mandrel or body portion I0 is threaded into the upper `end of a lower tubular packer body ll, to which is attached a packing actuator' l2 in the form of a guide.

A tapered expander I3 is mounted on the" body part Il. It is preferably prevented from turning with respect tothe latter by a key lilV secured to the exterior of the body and received Within along the line a keyway I5 in the expander; so as to permit relative longitudinal movement between the body II andv expander i3 while preventing rotation therebetween. When the tubular string C and body IIJ, II are elevated, the packing actuator I2 is moved toward the expander i3 to compress an intervening packing sleeve 6, surrounding the body, and force it outwardly into engagement with the wall of the casing B. Such actuation of the packing sleeve I6 only occurs when the tapered expander i3 is prevented from moving upwardly, which results from shifting of the expander within a plurality of slips l1, and outward expansion of the latter against the wall of the casing. Y Y

Y The slips I1 have tapered inner surfaces I3 cooperating with companion tapered surfaces i9 on the expander, Ythe inclination of such surfaces being such as to move the Yslips I1 outwardly toward the casing when the expander i3 is elevated. Conversely, lowering of the expander I3 with respect to the slips I1 permits the latter to release from the casing wall and move inwardly to retracted position.

It is, accordingly, apparent that elevation of the tubular string C and packer body I9, Il can effect anchoring of the tool, through engagement voi the slips I1 with the casing B under the influence of the tapered expander E3. Such elevation can also eiect compression or foreshortening of the rubber packing sleeve i6 between the expander I3 and guide I2, to produce its radial outward expansion into sealing engagement with the casing wall.

The slips I1 are held together for joint movement along the tapered expander i3 to and from engagement with the casing B by pin-connecting them to the lower ends of links 26, whose upper ends extend between the fingers 2| of a slip ring 22. This ring is also provided with a peripheral groove 23 into which pins 23, projecting in both directions from the sides of the links 2i), may extend, in order to couple all of the links and slips l1 for movement jointly with the slip ring 22. Outward movement of the upper ends of the links 26 is prevented by a stop ring 25 suitably secured to the slip ring 22.

The slip ring is connected to a drag and lock device 26 by a swivel mechanism 21, in order to permit rotation of the slips I1 and slip ring 22 without correspondingly rotating the drag device 26. The main purpose of the drag device 26 is to resist longitudinal movement of the slips I1 within the well casing B.

The drag device 26 includes an outer ratchet member 2B, consisting of a lower ring 29 threaded into an upper ratchet sleeve 30. The ratchet ring 29 and slip ring 22 are adjacent one another, and are provided with outwardly directed flanges 3l, 32 receivable within an interval circumferential groove 33 in a tie ring 34 having upper and lower inwardly directed anges 35, 36 disposed above and below the ratchet ring and tie ring flanges 3I, 32, respectively. For convenience of assembly, the tie ring 34 may be made in two halves that are moved radially inwardly to dispose the flanges 35, 36 above and below the ratchet ring and slip ring anges 3l, 32. This two-piece tie ring is prevented from coming apart by an encompassing circumierentially continuous sleeve 31, which is prevented from dropping off the ring by one or more screws 38 threaded into the ring and disposed within holes 39 in the sleeve. It is apparent that the tie ring 34 and the flanges 3l, 32 on the ratchet ring 29 and slip ring 22 4 form a swivel connection 21 between the drag device 26 and the slips I1. v

The drag and lock device 26 comprises the outer ratchet members 30, 29, which may slide relatively along the mandrel I0, or be coupled thereto. The sleeve 30 of this member is coupled to the lower end of the drag device 26, which includes a plurality of circumferentialy spaced outwardly bowed leaf springs 40, extending upwardly along the mandrel I0, and frictionally engaging the casing B.

The frictional engagement of the springs 40 with the casing B tends to resist longitudinal movement of the slips I1 through the well casing. Upon reaching the desired setting point in the casing, if the tubular mandrel I0 is permitted to move upwardly with respect to the drag device 26, such elevation would also elevate the lower packer body II, and, through the guide I2 and packing sleeve i6, elevate the expander I3 within the slips l1, since the latter are prevented from moving upwardly by the drag device. Such elevation of the expander I3 forces the slips I1 radially outward into anchoring engagement with the casing wall. With the slips I1 anchored to the casing B, the expander I3 is prevented from moving upwardly. Accordingly, a continuation of the upward movement of the tubular string C and body I0, II moves the guide ring i2 toward the expander I3, in order to foreshorten the packing sleeve i6 and shift it into firm sealing engagement with the casing B and the packer body II.

Lowering of the tubular string C and packer body I0, II with respect to the drag device 26 permits retraction of the packing sleeve I6 from the casing, and produces corresponding downward movement of the tapered expander I3, by virtue of engagement of the body shoulder 46 with an expander flange 41, so that the slips I1 are moved inwardly to retracted position. Such inward retraction will occur, since downward movement of the slips is prevented by the friction spring drag device 26.

It is to be noted that upward movement of the tubular body can effect anchoring of the packer A in packed-ofi condition within the well casing B, and that lowering o these members can effect release of the packer. In order to allow the tubular body I0, II to be elevated without anchoring the tool in the well casing, some means is provided for preventing the relative longitudinal movement between the slips I1 and tapered expander I3 upon elevation of the tubular body. In the present instance, such means is aorded by a ratchet or one-way clutch type of lock device disposed between the upper body or mandrel I6 and the ratchet sleeve 30.

The ratchet sleeve 36 has an inner surface 56 tapering upwardly and inwardly, that cooperates with a correspondingly tapered surface 5I on a segmented ring 52, to urge the ring inwardly, in order that the internal teeth 53 of the ring are disposed for clutching engagement with external ratchet teeth 54 formed on the periphery of the upper tubular body or mandrel i6. The segmented ring 52 includes a plurality of adjacent segments 55 (see Fig. 5) disposed a. substantial distance around the periphery of the mandrel I (I, such segments being urged inwardly by a split, contractile spring or snap ring 56 disposed within a peripheral groove 51 in the segments. This ring 56 tends to urge the segments 55 inwardly, to effect engagement of their ratchet teeth 53 with the companion teeth 54 on the mandrel.

Such ratchet teeth may be constituted by an upwardly facing ratchet or buttress type of thread 54 on the mandrel I0, engaging with a companion downwardly directed ratchet thread 53 formed jointly within the segments 55.

A stop t, in the form of a key, issecured to the ratchet sleeve tt, and engages one end of the segmented ring 52, to prevent rotation of the segmented ring relative to the ratchet sleeve. The other end of the ring 52 has an inwardh7 directed key or projection 59 disposed within a longitud# nal keyway 6i) in the mandrel I0.

Because of the ratchet or oneway`clutch type of lock device described, the mandrel ID can be moved downwardly without interference by the lock device, since the mandrel ratchet teeth 54 will merely ratchet freely over the companion teeth 53 on the segments 55. However, upward movement of the mandrel l0 will cause its teeth 54 to engage the segment teeth 53 and move the segments 55 upwardly with it, shifting them slightly toward the narrow portion of the tapered surface 55.? in the ratchet sleeve 3G, and wedging the segments iirmly between the mandrel l0 and ratchet sleeve 3G, which effectively couples the mandrel l0 and drag device 26 together against relative upward movement. In other words, the two parts It, 26 are locked together for upward movement as a unit. Accordingly, the slips Il are also locked to the mandrel HJ and will move upwardly with it.

When it is desired to shift the mandrel i0 upwardly within the drag device 2t, and with respect to the slips iI, in order to anchor the slips to the casing B, the tubular string C and upper body or :mandrel iii connected thereto are rotated a partial revolution, preferably to the right. Such rotation causes the mandrel l D to act upon the segment key 59 and expand the segments 55 outwardly to the extent in which their teeth 53 are completely out of engagement with the mandrel teeth 54. Such expansion will occur, since the other end of the segmented ring is prevented from moving by the stop 53 secured to the ratchet sleeve 30. When the mandrel is thus turned to free the segments 55 from its teeth 54, the mandrel vIt) may be moved upwardly within the segments 55 and the ratchet sleeve 30, in order to shift the expander `l'a upwardly within the slips il' and urge the latter into anchoring engage* ment with the casing B. As above indicated, a continuation of this upward movement foreshortens the packing sleeve I6 and expands it outwardly against the casing. v

When the slips I7 and packing i6 are to be retracted, it is `merely necessary to lower the tubular string C and mandrel I ll, which will lower the abutment I2 away from the expander i3, allowing the packing sleeve I6 to retract and also cause the body shoulder 46 to engage the expander shoulder 4l, shifting the expander downwardly relative to the slips l1 and eecting retraction of the latter. Such downward movement can occur without regard to the imposing of turning effort on the tubular string C and packer body lil, H because of the one-way ratchet arrangement between the mandrel threads 54 and segmented ring threads 53.

With the segmented ring 52 released by re verse turning of the tubular string C and packer `body l, Il, upward movement of these latter members will again automatically couple the mandrel li! to the ratchet sleeve 3U and drag device 26, in order that upward movement of the tubular string C and packer body I0, Il will be 6 ineffective to anchor the packer to the Well casing. The well tool, therefore, can'be removed to the top of the well bore.

As described above, the outwardly bowed leaf springs 40 engage the casing B to resist longitudinal movement of the slips l1 therewithin. These sp1ings`also resist rotation of the ratchet sleeve 3i? and enable rotation of the tubing string C and mandrel it to `effect unclutching of the segmented ring 52 from the mandrel teeth 54.

After the operation has been performed in the well bore, it is desired to remove the tool from the well casing. Such removal can be expedited by disconnecting the tubing string joints at the rotary table (not shown), through holding the stand of tubing above the table stationary, and through rotating the rotary table to rotate the tubing string C and the well tool A attached thereto. Such rotation ordinarily occurs to the right. If the drag device 26 shown in Figs. 1, 2, 3 were coupled directly to the ratchet sleeve 3U, rotation of the tubing string C and mandrel I0 would revolve the drag springs 4l) around the casing E, and might severely damage them. In i the form of the invention disclosed in the drawings, provision is made for uncoupling the drag device 26 from the remainder of the tool, in orderthat it need not rotate with the remainder of the.` tool.

In achieving the objective just mentioned, the lower ends of the springs 4l] are connected to a lower drag collarl'!) by an encompassing retainer ring Il and screws '12. The upper ends of the springs are similarly connected to an upper drag collar "Hic, slidable on the mandrel I0, by an encompassing ring lla and screws 72a. This lower drag collar has internal threads 73 adapted to engage andl cooperate with external threads 14 formedon the upper portion of a coupling or drag sleeve l5 threadedly, or otherwise, secured to the ratchet sleeve 35i. The threaded connection 13, 'Mis preferably left hand. Inadvertent separation between the-drag sleeve 15 and ratchet sleeve 3l] is prevented by a suitable lock screw 16 threaded into the ratchet sleeve and bearing against the drag sleeve.

Originally, the lower drag collar 10 occupies a position at the upper end of the drag sleeve 15, 'the extent of the upward threading of the collar being determined by engagement of its lug or projection l? with an outwardly directed lug or projection 'i8 on the drag sleeve. Rotation of the drag sleeve 'I5 to the right will effect downward feeding of the lower drag collar le along the sleeve 15, before the sleeve projection 'I8 can engage the collar projection '11, so as not to interfere with downward movement of the lower collar 7D along the sleeve. 'i8 will be engagedupon upward screwing of the lower collar 'IB on the sleeve 15, to limit the extent of such upward `movement and to prevent jamming of the threads 13, 14.

In order to prevent rotation of the ratchet sleeve 3c and drag sleeve 75 during manipulation of the segmented lock ring 52, a frictional restraint is imposed between the lower drag collar 'l0 and the drag sleeve 15. Such frictional restraint is obtained by causing a split, contractile brake shoe or ring .'8 to bear frictionally against the outer ends of the external threads N. This shoe is carried within the lower brake portion BU depending `from the lower retainer ring 1I, The shoe 19 may rest upon a flange or shoulder 8l extending inwardly from the brake portion 80, and is prevented from rotating by a holding screw The projections 11',

,V82 threaded through the brake portion 8D of the ring 8|, and received within a hole 83 in the shoe 19 diametrically opposite the open end or split portion 84 of the brake shoe.

The inherently contractile split brake shoe or band 19 provides enough frictional force against the sleeve threads 14 as to resist rotation of the ratchet sleeve 30 to an extent suicient to insure expansion of the segmented ring 52 to its unclutched position, upon rotation of the tubing string C and mandrel I to the right, as described above. The brake band or ring 19, however, does not exert suicient frictional force to transmit rotary motion of the coupling or drag sleeve to the drag springs and revolve the latter around the casing. Instead, the brake shoe 1Q will slip before that occurs.

A rubber wiper ring 85 may be secured in the upper end of the drag sleeve 15 to prevent foreign substances from moving downwardly through the clearance space between the drag sleeve 'l5 and mandrel |ll, and possibly clog the ratchet clutch mechanism SII- 54.

' A stop device 85 is also provided for insuring the pullingof the drag device 25 through the well casing B, irrespective of its upward or downward movement through the well casing. This stop device is adjustable and includes a two-part stop ring 81 disposed within a circumferential groove 88 in the mandrel. The two halves of this stop ring are separated by keys 89 welded er otherwise secured to the mandrel Hl. The stop ring hasreXternal threads 90 which project beyond the mandrel keys 89 for cooperation with an internally threaded sleeve 9| extending downwardly toward the drag sleeve 15, with which it is engageable. The upper end of the stop sleeve 9| is also engageable with the upper drag collar 10a, that is freely slidable along the mandrel I0.

It is to be noted that the threads 14 on the drag sleeve 15 do not extend throughout its length, but terminate a substantial distance above the upper end of the ratchet sleeve 30.

The unthreaded portion 15a of the sleeve has a diameter no greater than the root diameter of the threads 14, in order to permit the lower collar 10 to be disposed therealong. The unthreaded portion 15a of the sleeve is sutlicient in length to permit complete unscrewing of the lower drag collar 19 from the threaded portion 111, and also to accommodate the brake ring 19. Y

The well tool A is run in the well casing with the parts disposed in the position shown in Fig'. 1, except thatthe segmented ring 52 may be in its inward or clutching position. The stop sleeve 9| is adjusted by rotating it on the threaded stop ring 81 until its lower end engages the upper end of the drag sleeve 15. It is maintained in this adjusted position by a suitable screw 92 threaded through the sleeve 9| and bearing against the mandrel I0. The lower drag collar 10 is at the upper end of the drag sleeve 15, and the upper drag collar 10a is disposed a substantial distance above the stop sleeve 9|.

When the position in the well bore has been reached at which the tool is to be anchored in packed-off condition, the tubing string C and mandrel I9 are rotated to the right to unlatch the ratchet ring 52 from the mandrel, which permits the tubing string C and mandrel I0 to be elevated and effect engagement of the slips I1 and the packing IB with the wall of the well casing. Upward movement of the mandrel with- 1n the drag device 26 is permitted, because of the 8 I space that has been allowed between the upper end of the stop sleeve 15 and the upper drag collar 19a (see Fig. 1). Moreover, rotation of the ratchet sleeve 30 during turning of the mandrel is prevented by the frictional engagement of the brake shoe 19 upon the threads 14 of the drag sleeve 15, which is connected to the ratchet sleeve 30.

When the well tool A is to be removed from the well casing, the tubing string C and mandrel Il! are lowered to retract the slips I1 and the packing I6 to their initial positions shown in Fig. l. The tubing string C is then rotated to rotate the mandrel I9. Such rotation will expand the ratchet ring 52, and, through the ratchet ring 52 and stop key 56, will rotate the ratchet sleeve 3|) and the drag sleeve 15. Since the threaded interengagement 13, 14 between the drag sleeve 15 and lower drag collar 16 is left hand, and since the drag springs 45 engage the casing B to resist rotation of the lower drag collar, the rotation of the drag sleeve 15 to the right will thread the lower drag collar 1c downwardly along the sleeve 15, until the lower drag collar is completely unscrewed from the threaded portion of the drag sleeve. The friction force exerted by the brake shoe or band 19 against the drag sleeve threads 14 is only sucient to insure unclutching of the ratchet ring 52, but it is far less than the frictional force exerted by the drag springs 40 against the casing wall. As a result, the brake shoe 19 is incapable of preventing rotation of the drag sleeve 15 within the drag collar 10.

When the lower drag collar has been unscrewed from the threadd portion of the lower drag sleeve, as shown in Fig. 2, the upper drag collar 10a has been lowered to a location adjacent the upper end of the stop sleeve 9|.

It is evident that the lower drag collar 19 has been completely uncoupled from the drag sleeve 15, and that rotation of the drag sleeve 15 can occur freely within the lower drag collar 10 and the springs 49 without tending to rotate the latter. The tubing string C and mandrel IOVmay now be rotated to the extent desired, in elevating the tool within the well bore for the purpose of uncoupling the sections above the rotary table, without fear of revolving the drag springs 49 frictionally along and around the walls of the well casing B.

In addition to its function of permitting rotation of the mandrel Ill without rotating the drag device 25, after having been unscrewed from the drag sleeve 15, the drag and lock device disclosed ,performs afurtherrimportant function. It is to Abe noted that the unscrewing of the lower drag 'collar 1) from the drag sleeve '55 has located the upper drag collar 19a adjacent the stop sleeve 9|. It is also to be noted that the lower end of the stop sleeve si is adjacent the upper end of the drag sleeve 15, this latter position having occurred upon lowering of the mandrel l0 to effect retraction of the slips I1 and packing I6 from the well casing. Accordingly, regardless of the coupling or uncoupling position of the ratchet ring 52, it is impossible to reset the slips I1 and packing I6 against the casing B, since the mandrel l0 cannot be moved upwardly substantially with the respect to the slips |1. This action is prevented, because such upward movement is transmitted through the stop ring 81 and stop sleeve 9| to the upper drag collar 10a, through the drag springs 40 to the lower drag collar l0, and from the lower drag collar to thedrag sleeve 15, because ofthe engagement of the uppermost thread 13. on the lower collar 1U with the lower- 'most thread 'i4 on the threaded portion ofv the drag sleeve l5. Since the drag sleeve I5 is coupled to the slips Il through the ratchet sleeve 30, swivel 2'! and linkage 20, it is apparent that upward movement of the mandrel lli will also move the slips il upwardly with it, despite the unclutched position that the ratchet ring 5:2 might assume. The tool can be moved out of the hole as rapidly as possible without fear of inadvertently setting the vslips il, which might cause the tubing string on the tool to be pulled apart.

The stop sleeve 9! and drag device E@ arrange ment accomplishes yet a further function. Der ing lowering of the tocl in the well casing, the lower end oi the stop sleeve 9| engages the drag sleeve 15, and, through the threaded interccnH nection 14, "s3, moves the lower drag collar la downwardly in order to pull the drag springs di) through the casing. Similarly, during upward movement of mandrel ld in removing the tool from the well casing, the stop sleeve 9i engages the upper collar 'lila and again exerts a pulling action on the drag springs cil. This pulling action insures against buckling of the springs 48, that might accompany a pushing action, and avoids damage to or breakage of the lea-f springs.

After the lower drag collar l has become completely unthreaded from the coupling or drag sleeve 75, the only portions that can support the latter, together with its associated ratchet sleeve 39 and slips Il, in an elevated position with respect to the mandrel lil is the segmented ring 52. However, during rotation of the mandrel to the right, in uncoupling the tubing joints at the top of the well bore, the segmented ring 52 is expanded and no longer remains in coupled position. In View of this condition, there is then substantially nothing sustaining the weight of the drag sleeve l5, ratchet sleeve 30, links 2|] and slips l?, the latter dropping downwardly a slight amount, as determined by engagement of the lowermost external thread on the coupling sleeve l with the uppermost internal thread in the lower drag collar iti. Due to the inclination of the threads, the result is `an intermittent sliding and banging of the lowermost external thread 14 on the uppermost internal thread 73, with re sultant damage to the parts as the tubular mandrel iB and coupling sleeve 'l5 are being rotated.

The present invention offsets the tendency for the threads lll, 13 to engage after the lower drag collar Fil has been unccupled from the coupling sleeve l5. This is done by sustaining the weight of. the slips I1, links 253, swivel 2l, ratchet sleeve 30 and drag sleeve l5, and all of the other parts connected tc it. In the present instance, the weight is sustained by means of a plurality of helical springs $5 disposed around the lower pcrtion of the mandrel I8. Each spring is mounted on a guide pin 96 received within a bore 91 in the expander i3. The lower end of each Spring d5 rests upon the upper end of the `expander i3 and its upper end bears upon `the underside `of the slip ring 22.

The springs 35 exert suliicient force to tend to hold the slips l, links It, slip ring 22, swivel 2l, ratchet ring di) and drag sleeve i5 in an up ward position. The springs .95, however, do not exert sufficient ,force as to `wercome the frictional force of the drag springs All against the wall of the well casing :Se long as the `drag device is coupled to thesleeve le, the springs are comparatively 'i eiec'tive, and merely tend to -shift the slips il .upwardly with respect .to the expander I3 to retracted position. However, the springs 95 do not exert sufficient force :t0 prev clude shifting of the slips Il to expanded position when the segmented lock ring 52 has been` released and the expander I3 elevated upon upward movement of the mandrel Iii, body Il and packing l After the packing i6 and slips Il' have been returned to retracted position, the mandrel l0 may be rotated to the right to unthread the lowerv drag collar i0 along the coupling sleeve 15, until the internal andL external threads 13, 'M disengage, as shown in Fig. 2. When the parts are in this position, the helical springs 95 are effective to hold the coupling sleeve 15 in an upward position, to insure that the lowermost thread on the coupling sleeve is elevated above the uppermost thread in the lower drag collar 10. Accordingly, when the mandrel I0 is rotated to the right, in effecting uncoupling of the tubing joints at the top of the well bore, the lower thread on the coupling sleeve T5 cannot engage and ride :upon the upper thread in the drag collar 10, thus prei cluding damage to these threaded members.

Since the springs counterbalance or offset the weight of the slips Il, and the parts above the slips connected to them, they tend to hold the slips in their fully retracted position, `after the lower drag collar 1l) has been unthreaded from the drag sleeve 15, as limited by engagement of the drag sleeve l5 with the stop device 9|.

The inventor claims;

l. In a well tool for use in a well conduit:` a. rst member adapted for connection to a tubular string; a second member telesconically `arranged with respect to said rst member: means `Im' transmitting the turning effort of said first member to said second member; conduit engageable means cooperable with said. second member for resisting movement of said second member in said well conduit; means comprising a threaded connection between said conduit engageable means and second member for moving at least `part of said conduit engageable means longitudinally o! said members upon rotation of said nrst member and second member; fricticn brake means between said second member and Vconduit engageable means for resisting movement of said second member relative to said conduit engageable means, said friction brake means comprising 1a brake ring engaging a thread of said threaded connection.

2. In a well tool for use in a well conduit: Aa first member adapted for connection to a tubular string; a second member telescopically arranged with respect to said rst member; means for transmitting the turning effort of said rst member `to said second member; conduit engageable means cooperable with said second member for resisting movement of said second member in said well conduit; means comprising a threaded connection between said conduit engageable means and second member for moving at least part of said conduit engageable means longitudinally of said members upon rotation of said rst member and second member; friction brake means between said second member and conduit engageable means for resisting movement of said second member relative to said conduit engageable means, said friction brake means comprising an inherently contractile split ring engaging a thread of said threaded connection.

3. In a well tool for use in a well conduit: a first member `adapted for connection to a tubular running-in string; a second member telescopically arranged with respect to said first member; means for transmitting the turning effort of said first member to said second member; longitudinaliy spaced collars disposed around said members; conduit engageable drag springs secured to said collars; means comprising a threaded connection between one of said collars and said second member for moving said one collar longitudinally of said second member in response to rotation of said second member; and friction brake means between said one collar and said second member, said friction brake means comprising an inherently contractile split brake ring carried by said one collar and engaging said second member.

4. In a well tool for use in a Well conduit: a first member adapted for connection to a tubular running-in string; a second member telescopically arranged with respect to said rst member; means for transmitting the turning effort of said first member to said second member; longitudinally spaced collars disposed around said members; conduit engageable drag springs secured to said collars; means comprising a threaded connection between one of said collars and said second memc ber for moving said one collar longitudinally of said second member in response to rotation of said second member; friction brake means between said one collar and said second member, said friction brake means comprising an inherently contractile split brake ring carried by said one collar and engaging a thread on said second member, and means for preventing substantial rotation of said brake ring relative to said one collar.

5. In a well tool adapted to be lowered in a well conduit: normally retracted means; means for moving said normally retracted means into engagement with the well conduit; tubular means operatively connected to said moving means; releasable lock means operatively connected to said tubular means and normally retracted means for preventing substantial relative longitudinal movement between said normally retracted means and tubular means; a threaded sleeve secured to said lock means; friction means threaded on said sleeve and frictionally engageable with said conduit: and slippable brake means resisting relative rotation between said sleeve and friction means, said brake means comprising an inherently contractile split ring carried by said friction means and engagingr said sleeve.

6. In a Well tool adapted to be lowered in a well conduit: normally retracted means; means for moving said normally retracted means into engagement with the well conduit: tubular means operatively connected to said moving means; releasable lock means operatively connected to said tubular means and normallv retracted means for preventing substantial relative longitudinal movement between said normally retracted means and tubular means; a threaded sleeve secured to said lock means; friction means threaded on said sleeve and frictionally engageable with said conduit: slippable brake means resisting relative rotation between said sleeve and friction means, said brake means comprising an inherently contractible split ring carried bysaid friction means and engaging the threaded portion of said sleeve, and means for preventing substantial relative rotation between said ring and friction means.

7. In a well tool adapted to be lowered in a well conduit: normally retracted means; means for moving said normally retracted means into engagement with the well conduit; tubular means operatively connected to said moving means; re'- leasable lock means operatively connected to saidtubular means and normally retracted means for preventing substantial relative longitudinal movement between said normally retracted means' and tubular means; a sleeve secured to said lock means and having a threaded portion and an unthreaded portion; friction means threaded? on said threaded portion and frictionally engage-- able with said conduit, said friction means being movable along said threaded portion onto said' unthreaded portion in response to rotation ofV said tubular means and sleeve; and brake meanson said friction means comprising an inherently' contractible split ring engaging said sleeve.

8. In a well tool adapted to be lowered in a' well conduit: normally retracted means; means' for moving said normally retracted means into engagement with the well conduit; tubular` means operatively connected to said moving' means; releasable lock means operatively connected to said tubular means and normally retracted means for preventing substantial relative longitudinal movement between said normally retracted means and tubular means; a sleeve secured to said lock means and having a threaded portion and an unthreaded portion; longitudinally spaced collars disposed around said tubular Ineens; conduit engageable springs secured to said collars; one of said collars being threaded on said threaded portion of said sleeve and movable from said threaded portion onto said unthreaded portion in response to rotation of said tubular means and sleeve; and an inherently contractile split ring carried by said one collar and engaging the threaded portion of said sleeve to resist relative rotation between said sleeve and said one collar.

9. In a well tool adapted to be lowered in a well conduit: normally retracted means; means for moving said normally retracted means into engagement with the well conduit; tubular means operatively connected to said moving means; releasable lock means operatively connected to said tubular means and normally retracted means for preventing substantial relative longitudinal movement between said normally retracted means and tubular means; a sleeve secured to said lock means and having a threaded portion and an unthreaded portion; friction means threaded on said threaded portion and frictionally engageable with seid conduit, said friction means being movable along said threaded portion onto said unthreaded portion in response to rotation of said tubular means and sleeve; and means urging said sleeve in an upward direction when said friction means is disposed around said unthreaded portion of said sleeve.

10. In a well tool adapted to be lowered in a l well conduit: normally retracted slips; an expender coacting with said slips for urging them into engagement with the well conduit; tubular means operatively connected to said expander; releasable lock means operatively connected to said tubular means and slips for preventing substential relative longitudinal movement between said slips and tubular means; a sleeve secured to said lockvmeans and having a threaded portion and an unthreaded portion; friction means threaded on said threaded portion and frictionally engageable with said conduit, said friction means being movable along said threaded portion onto said unthreaded portion in response to rotation of said tubular means and sleeve; and means urging said sleeve in an upward di- 13 rection when said friction means is disposed around the unthreaded portion of said sleeve.

11. In a well tool adapted to be lowered in a well conduit: normally retracted slips; an expander coacting with said slips for urging them into engagement with the well conduit; tubular means operatively connected to said expander; releasable lock means operatively connected to said tubular means and slips for preventing substantial relative longitudinal movement between said slips and tubular means; a sleeve secured to said lock means and having a threaded portion and an unthreaded portion; friction means threaded on said threaded portion and frictionally engageable with said conduit, said friction means being movable along said threaded portion onto said unthreaded portion in response to rotation of said tubular means and sleeve; and means engaging said expander for urging said sleeve and slips in an upward direction when said friction means is disposed around the unthreaded portion of said sleeve.

12. In a well tool adapted to be lowered in a well conduit: normally retracted slips; an expander coacting with said slips for urging them into engagement with the well conduit; tubular means operatively connected to said expander; releasable lock means operatively connected to said tubular means and slips for preventing substantial relative longitudinal movement between said slips and tubular means; a sleeve secured to said lock means and having a threaded portion and an unthreaded portion; friction means threaded on said threaded portion and frictionally engageable with said conduit, said friction means being movable along said threaded portion onto said unthreaded portion in response to rotation of said tubular means and sleeve; at least one spring engaging said expander for urging said sleeve and slips in an upward direction, seid spring exerting less elevating force on said sleeve and slips than the friction force of said friction means against the conduit.

13. In a well tool adapted to be lowered in a well conduit: normally retracted slips; an expander for moving said slips into engagement with the well conduit; tubular means operatively connected to said expander; releasable lock means operatively connected to said tubular means and slips for preventing substantial relative longitudinal movement between said normally retracted slips and tubular means; friction means secured to said lock means and frictionally engageable with the conduit; and means urging said friction means and slips in an upward direction relative to said expander.

14. In a well tool adapted to be lowered in a Well conduit: normally retracted slips; an expander for moving said slips into engagement with the well conduit; tubular means operatively connected to said expander; releasable lock means operatively connected to said tubular means and slips for preventing substantial relative longitudinal movement between said normally retracted slips and tubular means; friction means secured to said lock means and frictionally engageable with the conduit; and at least one spring engaging said expander and lock means for urging said slips in an upward direction with respect to said expander, said spring exerting a lesser upward force than the force of friction of said friction means against the conduit.

15. In a well tool adapted to be lowered in a well conduit: normally retracted slips; an expander for moving said slips into engagement with the well conduit; tubular means operatively connected to said expander; releasable lock means operatively connected to said tubular means and slips for preventing substantial relative longitudinal movement between said normally retracted slips and tubular means; friction means secured to said lock means and frictionally engageable with the conduit; at least one guide pin slidable in said expander; and at least one spring disposed around said pin and engaging said expander and lock means for urging said lock means and slips in an upward direction relative to said expander.

16. In a well tool for use in a well conduit: a iirst member adapted for connection to a tubular string; a second member telescopically arranged with respect to said first member; means for transmitting the turning effort of said first member to said second member; conduit engageable means cooperable with said second member for resisting movement of said second member in said well conduit; means comprising a threaded connection between said conduit engageable means and one of said members for moving at least part of said conduit engageable means longitudinally of said members upon rotation of said rst member and second member; friction brake means between said one of said members and conduit engageable means for resisting movement of said one of said members relative to said conduit engageable means, said friction brake means comprising abrake ring for exerting a friction force between said one ofV said members and said conduit engageable means.

17. In a Well tool adapted to be lowered in a well conduit: normally retracted slips; an expander for moving said slips into engagement with the Well conduit; tubular means operatively connected to said expander; releasable lock means operatively connected to said tubular means and slips for preventing substantial relative longitudinal movement between said normally retracted slips and tubular means; friction means secured to said lock means and frictionally engageable with the conduit; and means urging said friction means and slips longitudinally with respect to said expander to enable said slips to shift inwardly toward retracted position.

18. In a well tool adapted to be lowered in a well conduit; normally retracted slips; an expander for moving said slips into engagement with the well conduit; tubular means operatively connected to said expander; releasable lock means operatively connected to said tubular means and slips for preventing substantial relative longitudinal movement between said normally retracted slips and tubular means; friction means secured to said lock means and frictionally engageable with the conduit; and at least one spring engaging said expander and lock means for urging said slips longitudinally with respect to said expander in a direction enabling said slips to shift inwardly toward retracted position.

REUBEN C. BAKER.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 2,300,438 Spang Nov. 3, 1942 2,368,400 Baker Jan. 30, 1945 2,368,401 Baker Jan. 30, 1945 

